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MD5(1) FreeBSD General Commands Manual MD5(1)
NAMEmd5, sha1, rmd160 -- calculate a message-digest fingerprint (checksum)
for a file
SYNOPSISmd5 [-pqrtx] [-sstring] [file...]
sha1 [-pqrtx] [-sstring] [file...]
rmd160 [-pqrtx] [-sstring] [file...]
DESCRIPTION
The md5, sha1 and rmd160 utilities take as input a message of arbitrary
length and produce as output a ``fingerprint'' or ``message digest'' of
the input. It is conjectured that it is computationally infeasible to
produce two messages having the same message digest, or to produce any
message having a given prespecified target message digest. The MD5,
SHA-1 and RIPEMD-160 algorithms are intended for digital signature appli-
cations, where a large file must be ``compressed'' in a secure manner
before being encrypted with a private (secret) key under a public-key
cryptosystem such as RSA.
MD5 has not yet (2001-09-03) been broken, but sufficient attacks have
been made that its security is in some doubt. The attacks on MD5 are in
the nature of finding ``collisions'' -- that is, multiple inputs which
hash to the same value; it is still unlikely for an attacker to be able
to determine the exact original input given a hash value.
The following options may be used in any combination and must precede any
files named on the command line. The hexadecimal checksum of each file
listed on the command line is printed after the options are processed.
-sstring
Print a checksum of the given string.
-p Echo stdin to stdout and append the checksum to stdout.
-q Quiet mode - only the checksum is printed out. Overrides the -r
option.
-r Reverses the format of the output. This helps with visual diffs.
Does nothing when combined with the -ptx options.
-t Run a built-in time trial.
-x Run a built-in test script.
DIAGNOSTICS
The md5, sha1 and rmd160 utilities exit 0 on success, and 1 if at least
one of the input files could not be read.
SEE ALSOcksum(1), md5(3), ripemd(3), sha(3)
R. Rivest, TheMD5Message-DigestAlgorithm, RFC1321.
J. Burrows, TheSecureHashStandard, FIPS PUB 180-1.
D. Eastlake and P. Jones, USSecureHashAlgorithm1, RFC 3174.
RIPEMD-160 is part of the ISO draft standard "ISO/IEC DIS 10118-3" on
dedicated hash functions.
Secure Hash Standard (SHS): http://csrc.nist.gov/cryptval/shs.html.
The RIPEMD-160 page:
http://www.esat.kuleuven.ac.be/~bosselae/ripemd160.html.
ACKNOWLEDGMENTS
This program is placed in the public domain for free general use by RSA
Data Security.
Support for SHA-1 and RIPEMD-160 has been added by Oliver Eikemeier
<eik@FreeBSD.org>.
FreeBSD 10.1 June 6, 2004 FreeBSD 10.1